Far from being inert and unchanging, a mere scaffolding to which the body's muscles and organs attach themselves, bones change constantly. Old bone cells die. New ones are born. But that's not all. According to an exciting new discovery, bones play a role in regulating blood sugar levels and fat deposits.

How is this possible? Bones act like a kind of endocrine organ, releasing osteocalcin, a hormone that influences bone formation. This hormone also increases both insulin production and the body's insulin sensitivity. It also reduces fat stores. Basically, osteocalcin levels in the bones are linked to blood sugar and body fat levels, and there is some sort of interaction back and forth.

It's a surprising finding for the uninitiated. However, some scientists are saying it makes sense when you think about it. Says Ronald Kahn, director of Harvard's Joslin Diabetes Center, "Obviously there does need to be some coordination between skeletal growth and body mass. If you carry around extra weight, your bones need to hold up under the extra pressure, so it's not surprising that your bones have a sense of body fat."

Did you hear about renowned Harvard scientist Barbara Kahn's latest published research? I blogged about it recently. Kahn and colleagues state, in a report published in Cell Metabolism (July 2007), that it's possible to use a simple blood test to detect the presence of a specific protein called RBP4. Kahn et al say the presence of RBP4 can be used to measure accumulations of deep belly fat. Underpinning this research is a belief that such accumulations of belly fat increase risk for metabolic syndrome, leading to various maladies including heart disease and diabetes.

However, not everyone accepts this point of view. A Yale research team says that deep belly fat may not be so evil after all. The researchers, who are based at Yale University School of Medicine in Chevy Chase, Maryland, assert that metabolic syndrome is caused not by belly fat but by insulin resistance in skeletal muscle. This resistance, they state, makes it tough for the body to manufacture glycogen, so - in people who are insulin resistant - energy that cannot be stored as glycogen gets diverted into fatty acid production, which then contributes to metabolic syndrome.

The team compared abdominal fat levels in young and healthy individuals, some of whom were insulin sensitive and some of whom were insulin resistant. The result? "There is absolutely no difference in the volume of abdominal fat," states Yale's Gerald I. Shulman, who was lead author of the study. Abdominal fat, says Dr. Shulman, "may come later in the course of the disease [metabolic syndrome], but it's not a primary, underlying factor."

More from the world of lab coats and Bunsen burners: a new Harvard University study (published in Science) suggests that Type 2 diabetics who are overweight could benefit from taking a couple of different drugs. The interesting thing is, these drugs were actually designed to treat other troubles - liver disease and a blood disorder. The former, ursodiol (usually used for liver and gallbladder issues), and the latter, Buphenyl (used to treat a serious yet rare blood disorder), were tested on obese, insulin-resistant mice. The result? The drugs had a normalizing effect on the mice's blood sugar levels.

Next step, of course, is to test this treatment out on humans and see if it has the same result. Shouldn't be too hard finding subjects, what with around twenty million Americans having Type 2 diabetes. Apparently, around ninety percent of that number are overweight or obese. Maybe this is a dumb question, but shouldn't we put at least as much effort into getting Type 2 diabetics to adopt healthier lifestyles and, er, drop some of that weight? In the meantime, I'm sure the manufacturers of these particular drugs are jumping for joy at this news...

While we're on the subject of books (see my previous blog), here's another new one: Staying Healthy with Diabetes - Nutrition & Meal Planning. Okay, there are a ton of books on the market about diabetes. There is no shortage of titles to consider. This might be one worth checking out though. Why? Because it comes courtesy of the Joslin Diabetes Center, a respected research institution affiliated with Harvard University. If you want the basic facts about diabetes and guidelines for staying healthy, this would be an authorative source of info.

Staying Healthy with Diabetes was written by Amy P. Campbell, a dietitian at Joslin, with the input of other Joslin staff. The aim of the book, says Campbell, is to de-mystify the subject of diabetes nutrition, especially in light of all the conflicting information on foods that turns up in the news with alarming regularity. The book describes the pros and cons of various types of foods, explains topics such as carb counting and the gylcemic index, and it also provides tips on lifestyle issues such as eating out healthily. Bottom line, says Campbell: "No foods are forbidden for people with diabetes."

The book, along with others in the "Staying Healthy" series, can be ordered at Joslin's online store or by calling 1-800-344-4501. The cost is $12.95 plus shipping.